class Solution {
public:
    int findPeakElement(vector<int>& nums) {
        int left = 0;
        int right = nums.size()-1;
        while(left<right)
        {
            int mid = left+(right-left)/2;
            if(nums[mid]>nums[mid+1]) right = mid;
            else left = mid+1;
        }
        return left;
    }
};